Seroepidemiology of Q fever in one-humped camel population in northeast Iran.

Coxiella burnetii, an obligate intracellular bacterium, is the causative agent of important zoonotic Q fever. It is the etiological agent of coxiellosis or Q fever in animals and human. This seroepidemiological survey was conducted to determine the seroprevalence of coxiellosis in increasingly camel raised population in vast area of Khorasan (North, South, and Razavi) provinces, northeast Iran. Using cluster random sampling strategy, 167 camels in 11 counties were selected as serum samples. Sera were assayed for antibody against C. burnetii using a Q fever ELISA kit. Logistic regression model was used to insight the contributing risk factor(s) of Q fever in the study area. C. burnetii was widely distributed throughout the study area. Seroprevalence of C. burnetii at animal level was 28.7 % [(95 % confidence interval (CI): 21.83, 35.56)] for camel populations. The proportion of seropositivity for camels in the studied counties ranged from 0 to 63.6 %. Logistic regression model showed that age correlated with seroprevalence of coxiellosis at the individual level in camels (P < 0.05). This study showed that a relatively high proportion of camels are seropositive to C. burnetii. Considering the economic, zoonotic, and public health importance of Q fever, percussion measures are to be implemented to prevent spreading of C. burnetii and zeroing the risk of Q fever in farm animals and human in this agro-ecologically and geopolitically important region.